In recent years, attempts have been made to improve the efficiency in the media processing of compressing and decompressing digitized video and/or audio data. Non-Patent Literature 1 discloses a multithreaded processor which improves the computing efficiency by executing a plurality of programs simultaneously.
Also, Patent Literature 1 discloses a technology for using a multithreaded processor. According to the technology disclosed in Patent Literature 1, a plurality of instruction streams (threads) are assigned with respective priorities of processing, and the instruction streams are executed in the descending order of the priorities. This technology dynamically achieves the processing performance required in units of instruction streams, and improves the whole processing efficiency.